# Circumference of a Circle

2 Steps
In this Instructable, we will dive into the exciting world of Circles.
Specifically the Circumference of a Circle.

Supplies:
Pencil (needed for it's erase-ability)
Paper

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## Step 1: Circle

Some basics of the Circle:

Circumference - the distance around the circle (aka the perimeter of the circle)
Radius - the distance from the center to any point on the circle
Diameter - the distance from a point on the circle to another point on the circle going
through the center (also twice the length of the Radius)
Pi - the symbol that represents the value 3.14 (actually Pi is a never ending number, but for our purposes 3.14 will be fine)

notanemo says: Oct 4, 2009. 12:31 AM
off the top of my head, pi is equal to 3.141592653589793. i have it to a million on my comp
mrpesas (author) in reply to notanemoMar 13, 2010. 8:50 PM
I only have it memorized to 3.14159.  I like to show my students the websites that let you search for your b-day, phone number, ss#, etc in pi
like this
http://www.angio.net/pi/piquery
joen says: Mar 13, 2010. 6:02 PM
in example 2 of step 2 you show that the radius is 12 in. Don't you mean the diameter?
mrpesas (author) in reply to joenMar 13, 2010. 8:47 PM
You are correct.  Thank you for pointing it out.  I fixed the page. :-)
thepelton says: Mar 13, 2010. 3:44 PM
I know it's not as precise, but 22/7 works for a close guesstimate.